Adjustable portable mortarboard



June 12, 1951* A. MUELLER ADJUSTABLE PORTABLE MORTAR BOARD 2 Sheets-Sheet 1 Filed J l 28, 1949' lberf Mueller y and A. MUELLER ADJUSTABLE PORTABLE MORTAR BOARD June 12, 1951 Filed July 28, 1949 2 Sheets-:Sheet 2 Albert Mueller y @W and w /flag Patented June 12, 1951 UNITED STATES PATENT OFFICE 2,556,207 ADJUSTABLE PORTABLE MORTARBOARD Albert Mueller, Columbus, Nebr. Application July 28, 1949, Serial No. 107,215

2 Claims.

provements in an adjustable portable mortar board and in general pertains to a vertically adjustable platform which may be detachably mounted upon a wheeled support for use by plasterers and briclrlayers as Well as others, and in general wherein a vertically adjustable supporting platform is desired.

The principal object of this invention is to provide an improved construction of easily vertically adjustable mortar board which may be selectively employed as a stationary platform or as a Wheeled platform as desired.

A further object of the invention is to provide an improved mortar board in accordance with the preceding object which shall be of unusually simple, lightweight and economical construction and which is capable of being formed from inexpensive and readily accessible conventional steel structural elements.

Yet another object of the invention is to provide an improved mortar board which is capable of easy vertical adjustment to a desired height, and which may be effectively locked at the desired adjusted position.

These, together with various ancillary features and objects of the invention which will later become apparentas the following description proceeds, are attained by the present invention, a preferred embodiment of which has been illustrated by way of example only in the accompanying drawings, wherein:

Figure 1 is a perspective view showing the improved mortar board mounted upon a wheeled ing the mortar board and wheeled support disassembled; and,

Figure 4 is a vertical transverse sectional view taken substantially upon the plane of the section line 4-4 of Figure 2 and illustrating certain structural features of the invention.

Referring now more specifically to the accompanying drawings, wherein like numerals designate similar parts throughout the various views, it will be seen that the numeral I indicates generally the improved adjustable mortar board construction, while the numeral I2 indicates the wheeled support which is detachable therefrom.

Referring primarily to Figure 3, it will be observed that the wheeled support |2 comprises a hollow frame of square or rectangular shape,

which may be conveniently formed of a plurality of angle iron members M which are welded or otherwise rigidly secured to each other at their extremities. Secured to the angle iron frame member in any desired manner is a transverse axle l6 upon which are journaled a pair of prefcrably rubber tired wheels l8 by means of which the support is rendered portable.

At what may be termed its rear end, the support It is provided with a pair of leg members 20 rigidly secured thereto, which legs may be conveniently formed of a single iron or sheet metal strap bent upon itself to provide supporting legs of the type shown in Figure 4. A handle indicated by the numeral 22 may likewise be formed of a single strip of material bent upon itself with its ends welded to the bent portions of the legs 29. As shown to the best advantage in Figure 4, the supporting frame [2 is provided upon its front angle iron memberl l with inwardly extending fastening pins 2 while the rear frame member is provided with a threaded aperture for receiving the threaded extremity of a crank 26.

The mortar board construction II] which fundamentally comprises an adjustable platform, includes a square or generally rectangular base consisting of angle iron members 28 which are welded or otherwise rigidly secured at their corners to form an open framework of the same general shape as that of the support 12, but of slightly less dimensions so that this base may be received within and rest upon angle iron members of the support I? as shown in Figure 4. For this purpose, the front angle iron members 28 of the base are provided with sockets, recesses or apertures through which the pins 24 may be received to thereby detachably fasten the front portion of the base to the support, and the rear angle iron frame member of the base is provided with an aperture at for the reception of the end of the crank 26 when the latter is inserted through the rear angle iron frame members of both the support and base as illustrated in Figure 4. By this means, the base may be securely positioned upon and fastened to the support to render the base and the platform carried thereby portable.

The mortar board includes a platform or supporting surface 32 which may be of any suitable construction, shape and size, and as illustrated consists of a number of planks secured together as by transversely disposed cleats 34 under the same, and suitably attached to the undersurface iron members 36 having vertically disposed cally adjusted positions of the platform 32.

form at the most convenient level. when mounted upon its wheeled support, the de- 3 flanges by means of which the platform is secured to the base.

A pair of crossed links 38 and 4B are pivotally secured to each of the angle iron members 36 as by pivot pins 42 and M, at the upper extremities of the crossed links, and a similar pair of crossed links 46 and 38 are pivoted 'at their lower extremities as at 50 and 52 to the angle iron frame members 28 at the sides of the base. The adjacent extremities of these upper and lower sets of crossed links are pivoted to each other by pivots consisting of crossbars 54 and which extend transverse the device as illustrated in Figures 2 and 3. Stabilizing links 58 and 6! are terminally pivoted to the crossbars 5d and 56 at one extremity, and at their other extremities are pivoted as at 62 and 64 to one of the lower and upper links 48 and 38 respectively.

The upper and lower sets of crossed links constitute leg assemblies which are foldable or collapsible to permit vertical adjustment of the platform 32 from the position shown in Figure 1 to that shown in Figures 2 and 3.

It will be seen that the function of the stabilizing links 58 and '59 which are provided in each of the two leg assemblies, serves to at all times maintain the platform 32 parallel to the base.

A latch means 'is provided to permit an effective locking of the leg assembly in various verti- For this purpose, the crossbar 58 is provided with a tubular shaft or sleeve 66 freely rotatable thereon between the two leg assemblies, and journaled on or rigidly attached to the sleeve E6 as by welding are a pair of parallel straps or bars 53 and which are provided with longitudinally displaced notches '!2 on their lower surfaces for selective engagement upon the other crossbar 58, while at their outer extremities the bars 58 and 18 are provided with a cross shaft T4 rigidly conmeeting the same.

From the foregoing, it is thought that the operation of the device will now be readily understood. The platform, tressel or mortar board 26, either removed from the portable support as shown in Figure 3 or mounted thereon as shown in Figure 4, may by means of the pivotal members of the leg assemblies be easily raised or lowered to the desired elevation, whereupon the latch members may have their notches i2 engaged 1;.

with the crossbar 54 to thereby lock the device v in desired adjusted position.

It should be noted that the present device readily lends itself to use by bricklayers or plasterers in that the device either mounted upon its wheeled support or resting upon its supporting base may be adjusted in its lowered position to receive bricks, mortar or the like, as a workman commences the bricklaying or plastering operation. As the worker proceeds to higher levels, the device is readily adjusted to position the plat- In addition,

will readily occur to those skilled in the art after a consideration of the foregoing specification and accompanying drawings, it is not desired to limit the invention to the exact construction shown and described, but all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.

Having described the invention, what is claimed as new is 1. An adjustable portable mortar board including a wheeled support, a base detachably mounted upon said support, a platform, means adjustably mounting said platform on said base, said means comprising a pair of collapsible legs, each leg including upper and lower pairs of crossed links whose opposite ends are pivoted to said base and platform and whose adjacent ends are terminally pivoted to each other, crossbars connecting the pivots of said adjustable ends, and notched latches pivoted to one crossbar and engageable with the other crossbar, a pair of stabilizer bars each pivoted to a crossbar and pivoted to an upper and lower link.

2. An adjustable portable mortar board including a wheeled support, a base detachably mounted upon said support, a platform, means adjustably mounting said platform on said base, said means comprising a pair of collapsible legs, each leg including upper and lower pairs of crossed links whose opposite ends are pivoted to said base and platform and whose adjacent ends are terminally pivoted to each other, crossbars connecting the pivots of said adjustable ends, and notched latches pivoted to one crossbar and engageable with the other crossbar, said support and base having complementary sockets and pins and a bolt for securing said base to said support, said support and base each consisting of open, angle iron frames nested together.

ALBERT MUELLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 722,165 Taft Mar. 3, 1903 2,304,622 Barrett Dec. 8, 1942 2,436,647 Huey Feb. 24, 1948 2,506,860 Dimon May 9, 1950 2,512,534 Shaw, Jr June 20, 1950 

